LITTLE ROCK, Arkansas — A Muslim convert who already was under federal investigation pleaded not guilty Tuesday in what police called a likely "political and religious" attack that killed a young soldier at a military recruiting center.

Abdulhakim Muhammad, 23, was charged in Monday's death of Pvt. William Long, 23, of Conway outside an Army-Navy Career Center. He pleaded not guilty to a capital murder charge and was ordered held without bail.

A prosecutor said Muhammad admitted shooting Long and another soldier "because of what they had done to Muslims in the past."

An FBI-led joint terrorism task force based in the southern United States has been investigating Muhammad since he returned to the United States from Yemen, a law enforcement official said. The suspect had been arrested and jailed in Yemen at some point for using a Somali passport, the official said. The time of that arrest was not immediately clear.

The official, who spoke on condition of anonymity, was not authorized to discuss the investigation.

An FBI spokesman did not immediately respond to a call seeking comment.

Assistant U.S. Attorney Pat Harris said no decision has been made on whether to pursue federal charges against Muhammad. "We're consulting with a lot of people on what, if any, charges can be filed against him," Harris said.

Interviews with police show he "probably had political and religious motives for the attack," the chief said.

"We believe that it's associated with his disagreement over the military operations," Thomas said.

Police Sgt. Cassandra Davis said Tuesday it wasn't known when Muhammad began planning the attack.

Deputy Prosecutor Scott Duncan said Muhammad told investigators that "he would have killed more soldiers had they been in the parking lot." Long and Ezeagwula were targeted as they stood outside the recruiting center smoking cigarettes.

Muhammad did not speak during the brief hearing before Judge Alice Lightle.

John Rehrauer, spokesman for the Pulaski County jail, said the department was handling Muhammad as it does other high-profile cases.

'Protective custody'
"He is in some protective custody, in a higher-security unit in a cell by himself," Rehrauer said.

He said he didn't know of any threats against Muhammad and said jailers did not believe he was in any greater danger than previous high-profile people handled at the prison.

The two soldiers had recently completed basic training and had volunteered for a program to recruit others to the military, said Lt. Col. Thomas F. Artis of the Oklahoma City Recruiting Battalion, which oversees the Little Rock office.